diff --git a/lighthouse-core/scripts/roll-to-devtools.sh b/lighthouse-core/scripts/roll-to-devtools.sh
index b1bdfaed6494..2270d8fe963f 100755
--- a/lighthouse-core/scripts/roll-to-devtools.sh
+++ b/lighthouse-core/scripts/roll-to-devtools.sh
@@ -17,13 +17,12 @@
 # with a custom devtools location (could be path to standalone checkout):
 #   yarn devtools ~/code/devtools/devtools-frontend
 
+
+set -euo pipefail
+
 check="\033[96m ✓\033[39m"
 
-if [[ -n "$1" ]]; then
-  dt_dir="$1"
-else
-  dt_dir="$HOME/src/devtools/devtools-frontend"
-fi
+dt_dir="${1:-$HOME/src/devtools/devtools-frontend}"
 
 if [[ ! -d "$dt_dir" || ! -a "$dt_dir/front_end/OWNERS" ]]; then
   echo -e "\033[31m✖ Error!\033[39m"
@@ -48,10 +47,14 @@ echo -e "$check lighthouse-dt-bundle copied."
 
 # generate bundle.d.ts
 npx tsc --allowJs --declaration --emitDeclarationOnly dist/report/bundle.esm.js
+
 # Exports of report/clients/bundle.js can possibly be mistakenly overriden by tsc.
-sed -i '' 's/export type DOM = any;//' dist/report/bundle.esm.d.ts
-sed -i '' 's/export type ReportRenderer = any;//' dist/report/bundle.esm.d.ts
-sed -i '' 's/export type ReportUIFeatures = any;//' dist/report/bundle.esm.d.ts
+# Funky sed inplace command so we support both GNU sed and BSD sed (used by GHA devtools runner on macos)
+#     https://stackoverflow.com/a/22084103/89484
+sed -i.bak 's/export type DOM = any;//' dist/report/bundle.esm.d.ts
+sed -i.bak 's/export type ReportRenderer = any;//' dist/report/bundle.esm.d.ts
+sed -i.bak 's/export type ReportUIFeatures = any;//' dist/report/bundle.esm.d.ts
+
 
 # copy report code $fe_lh_dir
 fe_lh_report_dir="$fe_lh_dir/report/"